US4481666A
Expired / Lapsed
US
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Reading-out apparatus
Assignee: Kowa Co Ltd
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Filing: 1981-12-18
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Granted: 1984-11-06
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Expires: 2001-12-18
Abstract
Abstract In an apparatus for reading-out features such as characters and marks recorded on an object such as labels, boxes and cards, the object is scanned by a linear CCD array to produce a video signal and a background level is detected from the video signal on the basis of an edge signal derived from the video signal. A plurality of slice levels having span and pitch adjusted according to said background level are generated and the video signal is compared with the slice levels to produce an output video signal. Even if the level of the video signal changes abruptly, it is possible to obtain more accurate output video signal and to remove error in pattern recognition. In another preferred embodiment, an amplitude of the video signal is adjusted by a variable attenuator in accordance with the detected background level.
Inventors
- 👤 Hideaki Niwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:07
CPC Classifications
G; G06; G06V; G06V30/00; G06V30/10; G06V30/16; G06V30/162
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
104 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means for exclusively detecting a background level corresponding to a background of the object from the video signal supplied fom said picking-up means; control means comprising a slice level setting circuit for adjusting the span and pitch of a plurality of slice levels according to said background level; and a comparator circuit for generating an output video signal by comparing the video signal supplied from said picking-up means with said slice levels.
Claim 2
Independent Claim
104 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means for exclusively detecting a background level corresponding to a background of the object from the video signal supplied fom said picking-up means; control means comprising a slice level setting circuit for adjusting the span and pitch of a plurality of slice levels according to said background level; and a comparator circuit for generating an output video signal by comparing the video signal supplied from said picking-up means with said slice levels.
Claim 3
Dependent Claim
57 words
An apparatus according to claim 1, wherein said slice level setting circuit comprises a counter for counting clock pulses to produce a count signal and a multiplying digital to analog converter for receiving said background level and count signal to produce successively a plurality of slice levels having the span and pitch depending upon the background level.
Claim 4
Dependent Claim
54 words
An apparatus according to claim 1, wherein said slice level setting circuit comprises a voltage divider formed by a series circuit of resistors having one end connected to a video signal input terminal, the other end connected to a reference potential point and a plurality of output terminals connected to junctions between successive resistors.
Claim 5
Dependent Claim
15 words
An apparatus according to claim 1, wherein said picking-up means comprises a linear CCD array.
Claim 6
Dependent Claim
74 words
An apparatus according to claim 1, wherein said background level detecting means comprises an edge detector for detecting an edge signal from the video signal, a gate pulse generator for receiving the edge signal to produce a gate signal, a gate circuit for gating the video signal in response to the gate signal to produce a gated video signal and a rectification circuit for rectifying the gated video signal to produce the background level.
Claim 7
Dependent Claim
59 words
An apparatus according to claim 5, wherein said edge detector comprises a delay circuit to produce a delayed video signal, a pair of potentiometers for producing slightly attenuated video signal and delayed video signal, respectively and a pair of comparators for comparing the video signal and attenuated-delayed video signal and the attenuated video signal and delayed video signal, respectively.
Claim 8
Dependent Claim
55 words
An apparatus according to claim 6, wherein said edge detector further comprises a monostable multivibrator triggered by an output signal from said comparators to produce a pulse having a given time duration and a logical circuit for producing a product of the output signal from the comparators and the output pulse from the monostable multivibrator.
Claim 9
Dependent Claim
28 words
An apparatus according to claim 1, wherein said control means comprises a variable attenuator for adjusting the magnitude of the video signal in accordance with the background level.
Claim 10
Dependent Claim
35 words
An apparatus according to claim 8, further comprising an integrating circuit for producing an envelope signal of the video signal and means for supplying the envelope signal to the comparator circuit as the slice level.
Claim 11
Dependent Claim
54 words
An apparatus according to claim 9, further comprising a comparator for comparing the envelope signal with the video signal to detect an abrupt variation of the video signal, a video switch connected between the variable attenuator and the integrating circuit and being turned off upon detection of said abrupt variation of the video signal.
Claim 12
Dependent Claim
43 words
An apparatus according to claim 10, further comprising a switch connected in the background level detecting means and being turned on in response to the detection of the abrupt variation of the video signal to change the background level to a predetermined level.
Claim 13
Independent Claim
154 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means comprising an edge detector for detecting an edge signal from the video signal, a gate pulse generator for receiving the edge signal to produce a gate signal, a gate circuit for gating the video signal in response to the gate signal to produce a gated video signal and a rectification circuit for rectifying the gated video signal to produce a background level corresponding to a background of the object from the video signal supplied from said picking-up means; control means for relatively adjusting at least one of a slice level and the magnitude of the video signal according to said background level; and a comparator circuit for generating an output video signal by comparing the video signal with said slice level.
Claim 14
Independent Claim
154 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means comprising an edge detector for detecting an edge signal from the video signal, a gate pulse generator for receiving the edge signal to produce a gate signal, a gate circuit for gating the video signal in response to the gate signal to produce a gated video signal and a rectification circuit for rectifying the gated video signal to produce a background level corresponding to a background of the object from the video signal supplied from said picking-up means; control means for relatively adjusting at least one of a slice level and the magnitude of the video signal according to said background level; and a comparator circuit for generating an output video signal by comparing the video signal with said slice level.
Claim 15
Dependent Claim
62 words
An apparatus according to claim 12, wherein said edge detector comprises a delay circuit to produce a delayed video signal, a pair of potentiometers for producing a slightly attenuated video signal and an attenuated delayed video signal, respectively, and a pair of comparators for comparing the video signal and attenuated-delayed video signal and the attenuated video signal and delayed video signal, respectively.
Claim 16
Dependent Claim
55 words
An apparatus according to claim 13, wherein said edge detector further comprises a monostable multivibrator triggered by an output signal from said comparators to produce a pulse having a given time duration and a logical circuit for producing a product of the output signal from the comparators and the output pulse from the monostable multivibrator.
Claim 17
Independent Claim
110 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means for exclusively detecting a background level corresponding to a background of the object from the video signal supplied from said picking-up means; control means comprising a variable attenuator for adjusting the magnitude of the video signal according to said background level; an integrating circuit for producing an envelope signal of the video signal; and a comparator circuit for generating an output video signal by comparing the video signal supplied from said picking-up means with said envelope signal.
Claim 18
Independent Claim
110 words
An apparatus for reading-out features such as characters and marks, comprising picking-up means for generating a video signal by scanning an object having the features to be read out; background level detecting means for exclusively detecting a background level corresponding to a background of the object from the video signal supplied from said picking-up means; control means comprising a variable attenuator for adjusting the magnitude of the video signal according to said background level; an integrating circuit for producing an envelope signal of the video signal; and a comparator circuit for generating an output video signal by comparing the video signal supplied from said picking-up means with said envelope signal.
Claim 19
Dependent Claim
56 words
An apparatus according to claim 15, further comprising a second comparator for comparing the envelope signal with the video signal to detect an abrupt variation of the video signal, and a video switch connected between the variable attenuator and the integrating circuit and being turned off upon detection of said abrupt variation of the video signal.
Claim 20
Dependent Claim
43 words
An apparatus according to claim 16, further comprising a switch connected in the background level detecting means and being turned on in response to the detection of the abrupt variation of the video signal to change the background level to a predetermined level.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-06 | 1988-05-07 | 1988-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-06 | 1992-05-07 | 1992-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-06 | 1996-05-07 | 1996-11-06 | $7700.00 | Window Closed / Lapsed |